1. Field
Embodiments of the present invention relate to an electric caliper brake with parking function which produces braking force through an electric actuator and may produce braking force even if power is off.
2. Description of the Related Art
An electric caliper brake generally employs a motor drive unit operated by electricity as a power source of a driving unit to apply supplemental pressure to the disc of a hydraulic disc brake.
Korean Patent Application Publication No. 2011-0057764 discloses an example of the electric caliper brake. According to this document, the electric caliper brake includes a disc to rotate with a wheel of a vehicle, a pair of pad plates disposed on both sides of the disc to apply pressure to the disc, a pressing member (a piston) installed to be movable forward and backward to apply pressure to the pad plates, a motor to produce driving power, a gear assembly to amplify the driving force produced by the motor, and a spindle to transfer rotational power of the motor from the gear assembly to the pressing member.
The electric caliper brake further includes a self-locking structure which maintains braking force even when power is off after braking is completed. Herein, the disclosed self-locking structure is a latch structure provided with a separate electronic component, i.e., a solenoid. In this structure, movement of a gear is restricted when a movement shaft connected to the solenoid is fitted into a locking hole formed in the gear.
However, in the case of the electric caliper brake as above, a separate electronic component (a solenoid) needs to be added to maintain braking force, and the locking function may be performed only when the movement shaft and locking hole configuring the latch structure are accurately aligned.
Moreover, due to the function of adjusting the position of the pressing member (the piston) according to wear of the friction pad contacting the disc other than the braking function, utilization of an installation space according to use of the electronic component (the solenoid), and connection of electric circuits, which are additionally needed, the electric caliper brake as above may be disadvantageous in view of cost and manufacturing.